chmod- allows the user to change the permission access of  a file or directory.

su- allow the user to access the terminal as a super user for one command.

 

sudo-let the user control the terminal as a super user

 

 

chown- changes the ownership of a particular file.

 

 

passwd- allows user to change log in password.

 

ps- to display the  active processes

 

 

kill- is used to terminate the process.

 

 

printenv- displays a list of the environment variables